1. Field of the Invention
The present invention relates generally to an apparatus for holding a slider during the threading of a slide fastener chain through the slider in the manufacture of a slide fastener and particularly to a slider holding apparatus especially adapted for threading through a slider of a slide fastener chain having a succession of fabric pieces attached to each of the opposed longitudinal marginal edges thereof.
2. Description of the Prior Art
A conventional slider holding apparatus of the type described includes a holder body that is vertically movable and has, at its upper end, a first slider seat half. A supporting arm is pivotally mounted on the holder body, and is angularly movable between an inclined position and an upright position. Another (or "second") slider seat half is mounted at the upper end of the holder body, and coacts with the first slider seat half to provide a slider seat upon which the slider resets. A locking lever is also pivotally mounted on the holder body, and has a locking projection at its upper end. The locking lever is normally urged by a spring to cause a projection to engage with an aperture of a pull tab of the slider resting on the slider seat. Once the slider is thus firmly held on the slider seat, the slider holding apparatus is moved upwardly until the slider held on the slider seat comes into registry with a feeding path of a continuous slide fastener chain. Eventually, the continuous slide fastener chain is threaded through the slider. A typical slider holding apparatus of this type is disclosed in Japanese Patent Laid-open Publication No. 63-5704.
This known apparatus is very satisfactory when used for threading a slide fastener chain proper through a slider, that is, a slide fastener chain with no fabric pieces attached to its opposed longitudinal edges. However, known apparatus are unsuitable for threading a slide fastener chain with a succession of fabric pieces already attached to each of the opposed longitudinal edges thereof. The fabric pieces are usually heavy and hang downward from the slide fastener chain on its opposite sides. Forcing the slide fastener chain with such heavy fabric pieces through the slider causes the holding apparatus to wobble, and makes the slider come out of the feeding path of the slide fastener chain, so that the threading operation fails. Particularly, where the threading operation is automated, the matter is made much worse, since the threading operation automatically continues, even if the slider comes out of the feeding path of the slide fastener chain. Consequently, in the automatized apparatus, the slider-threading operation oftentimes is interrupted, thus considerably lowering the manufacturing efficiency of slide fasteners.